Stoker feed worm structure



Aug. 11, 1942.

H. H. FITCH STOKER FEED WORM STRUCTURE originalriled May 21, 1938 FIE, l //5 /Za 1 //4 INVENTOR. /fuKs/ffL h. 2"/ 76W.

BY` I M l ATTORN Yi Patente-d Aug. 11, 1942 sToKEn FEED WORM STRUCTURE,

Hurshel H.Y Fitch, Auburn, Ind., assignor to Auburn Foundry Inc., Auburn, Ind., a corporation original application May 21, 193s, serial No. 209,278. Divided and this application`July 23,

1941, serial No. 403,729

12 Claims. (C1. 1798-213)` Y This invention relates to a stoker feed worm structure for supplying solid fuel from a hopper, but more particularly a bin, to a furnace, boiler, or the like, arrangement.

This application is a divisionvof the copending application, Serial No. 209,278 filed May 21, 1938, entitled, Line drive and feed for stoker, the last mentioned being a continuation-in-part of application Serial No. 90,090, now Patent No. 2,208,751 dated July 23, 1940.

One object of this invention is to provide in a fuel feeding worm for a solid fuel consuming vice such as of the underfeed retort type, a detachable construction so that the fuel feeding construction may be readily adjusted in the field, more particularly when the solid fuel consuming device is associated with a bin for bin feed supply of fuel to the fuel consuming device.

This invention has as its primary feature, the parting of the fuel feeding worm and the worm enclosing tube structure and associating the parted portions of the worm by a reversible driving connection and the parting of the worm enclosing tube, the latter parting permitting access to the reversible detachable vdriving connection between the worm parts so that the length of the worm may be readily adjusted, as hereinafter pointed out and more particularly accurately adjusted without the necessity of welding and like operations in the eld.

It is to be understood that the worm is supplied in standard lengths of different sizes and that the Worm enclosing tube is likewise supplied in different lengths of standard size and accordingly, the invention permits in the field of the use of standard length worms or a fraction thereof sufficient to obtain the desired approximately overall worm lengths. This worm section or length may be readily cut with a hacksaw or the like. When associated with the adjacent end of another and aligned worm length and through the instrumentality of the present invention, the two or more worm lengths connected together may be accurately adjusted to the required overall worm length, as will be more fully set forth hereinafter. The adjacent ends of the two worm enclosing tubes are similarly enclosed by a telescopically and enveloping tube, which is of suicient length to permit of adjustment axially of the resulting enclosing overall tube and also permit of sufficient accommodation so that the tube parts may be adjusted in accordance with worm requirements.

A further feature of the invention consists in so arranging the parts that the connection between the worm sections and the connection between the worm enclosing tube sections is of such character that the cross-sectional area therebetween at any transverse section is substantially the same, thereby preventing any constriction in the fuel supply.

Other objects and features will be set forth more fully hereinafter.

The full nature of the invention will be understood from the accompanying drawing and thev following description and claims.

In the drawing Fig. 1 is a longitudinal, sectional view through a half portion of a conventional solid fuel consuming device, such as an underfeed stoker arrangement, together with the fuel supplying worm and the worm enclosing tube structures, the latter including detachable connections shown more clearly in the lefthand portion of said figure.

Fig. 2 isa longitudinal central sectional view on a considerably larger scale of the worm tube structure embodying the detachable connection.

Fig. 3 is an elevational view of the Worm connector per se.

Fig. 4 is a transverse, sectional view thereof taken on line 4-4 of Fig. 3 and in the direction of the arrows.

Fig. 5 is a view similar to Fig. 2 of a modified form of the invention showing the coupling end of a driving worm.

Fig. 6 is a view similar to Fig. 4 and taken on line 6-6 of Fig. 3 and in the direction of thel arrows. Y

In Fig. V1 of the drawing there is illustrated a portion of a main'casting H0 having a curved channel rI Il extending therethrough and terminating in .a projecting collar portion H2 of tubular character. It also includes a central throat H3.V A casting H4 superimposed thereabove includes the annular chamber H5 formed by thevthroat portion H6. Superposed thereabove is the tuyre construction H1 having. the fuel receiving portion or hopper H8 and the airsupplying openings H9 which communicate with the rchamber |20 within the tuyrestructure. as at |2| with the chamber H5 which in turn communicates as at |22 with the chamber |23.

Seated in the portion H2 is a worm enclosing tube |13. This worm enclosing tube has its retort end seated in the socket |14. 'I'here also is provided a worm enclosing tube |16. These two tube sections are in axial alignment and an enveloping connecting tube |15 'constitutes the splice or sleeve and said tube |15 has This chamber |20 in turn communicates` an appreciable length at each end telescoping the adjacent closed ends of the aligned tubes.

Within the tube is a worm |43. This worm is sectionalized and it includes a central portion supporting a night. In Fig. 2 the central portion of one worm is indicated by the numeral |86a and the Worm nightithereon by the numeral |43a. The tube |13 is shown enveloped by tube |15 and the latter at its opposite end envelopes the tube |16. Within that end of the tube is the shaft portion |86b of the aligned worm portion andv having the night |4319 thereon.

Referring more particularly to'rFigs.-2 to 4'; in-

clusive, it will be noted that between the adja` cent ends of the tubes |13 and |16, said ends being designated by the subscriptl a, therev is' provided a space and this spacevariesfin-accordance with the adjustment. It will be noted-see Fig. 2-the sleeve |15 telescopes both of the before mentioned aligned tubes and provides a space therebetweendesignated by the numeral This same figure shows the night |43a terminates at |43a' and that the night |4317 terminates at |43b'.

Mounted in said enlargement is a spiral strip that on one edge carries a flight' |02, the pitch of which corresponds with that of nights |43a and |43b. The spiral strip is-arranged in tubular form providing the coaxial bore |04 therethrough. All' adjacentv portions of the two adjacent turns are spaced apart to form a spiral passage |03.

|8611, and |8612. The passage |03 permits flights |43a and |43b t'o projectl through or beyondthe strip adjacent night |02'. The effective diameter of night |02 is at least equal to but may be greater than that' of M3U. and |4317, as illustrated.

Abutment |05 in the bore |04 serves as a stop and may be engaged by ends of shafts |8611. and |86b, if desired. Strip |0| mounts two embossments |06 apertured at |01 and threaded'to receive headless set screws |08 for clampingly locking the shafts |86a and |861) to strip |;0| in adjusted position in the borev |04- thereof.

The two worms abut against the small stop in the inside of the coupling. The worm |06a drives against this stop or lug. The set screws are used on the coupling simply to keep the worms from backing out of the coupling.

It will be noted the coupling is slightly larger in diameter than the main worm portions. This increase in night and tube diameter provides an increased fuel carrying capacity because the extra metal that is put into this coupling would' normally cut down the carrying capacity of the device at the coupled connection. This increase in` diameter, however, offsets this loss in volume. As shown in the drawing, the increased diameter of the coupling substantially conforms to the outside diameter of the tubes enclosing the worm portions |4311 and |4312.

The employment of this coupling arrangement eliminatesv welding in the neld and permits the parts to be sectionalized so that extremely long parts are not required. YThis coupling arrangement also provides a much simpler installation. In obtaining the desired overall worm length, either worm element |43a or |431) may be cut on square at its edges |43a and |43b', respectively, and associated with the coupling.

In Fig. 5 there is illustrated a modified form of the invention. In this figure, numerals of the two hundred series indicate parts like or similar The bore receives the shaft portions to those illustrated in Figs. 2 and 3 and designated by similar numerals of the one hundred series.

This embodiment contemplates the formation of the spiral or worm coupling portion integral with the worm portion 28m-243m The adjacent worm-see left hand end of Fig. 2-is associatedtherewith and secured by set screw 208.

Preferably in each modincation the arrangement is such that power (rotation) is applied so that the coupling tends to automatically lock the parts together.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The. several modifications described herein as well as others which will readily suggest themselves'to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. In a stoker structure tube means, a pair of aligned fuel feeding worms therein, the pitch and direction of nights therein being substantially the same, and atubular coupling in the tube means including avworm shaft receiving bore and a spiral passage for worm night reception and having external night means similar to the worm nights.

2. In a stoker structure, a coupling of thecharacter denned by claim l, characterized by the addition of stop means-within the bore.

3. In a stoker structure, acoupling of the character denned by claim 1, characterized by the addition of spaced set screws for locking each of the worms in adjusted position inthe coupling.

4. In a stoker structure, a coupling of the character defined by claim 1, characterized by the addition of spaced set screws for locking each of the worms in adjusted position in the coupling, and stop means for worm shaft engagement within the bore.

5. In a stoker structure asdenned by claim l, characterized by the tube means including a pair of axially aligned but spaced tubes, and an externalvtubular connection therebetween forming an enlarged chamber between tube ends, said coupling night means having an eiiective external diameter greater than that of the interior of the aligned tubes and positioned in the enlarged chamber.

6. In a Stoker structure, a coupling of the character denned by claim 1, characterized by the addition of spaced set screws for locking each of the worms in adjusted position in the coupling, and stop means for worm shaft engagement within the bore, said tube means including a pair of axially aligned, but spaced tubes, and an external tubular connection therebetween forming an enlarged chamber between tube ends, said coupling night means having an effect-ive external diameter greater than that of the interior of the aligned tubes and positioned in the enlarged chamber.

'7. A worm construction for stokers and the like, including a pair of axially aligned worms having nights of light pitch, and a coupling therefor including a worm night receiving passage arrangement and night means thereon adjacent the passage for worm night engagement, the worm nights projecting through the passage arrangement.

8. A construction as denned by claim 7, characterized by the coupling telescopically receiving the adjacent shaft portions of the aligned Worms and including an internal stop between the coupling ends.

9. A construction as defined by claim 7, characterized by the addition of spaced locking means carried by the coupling and selectively locking each Worm thereto.

10. A worm construction for stokers and the like, including a pair of axially aligned worms having flights o-f like pitch and a coupling arrangement rigid With one worm and including a l0 worm ilight receiving passage and flight means thereon adjacent the passage for engagement with the worm ight of the adjacent worm, the last mentioned Worm flight projecting through the passage.

11. A worm construction as defined by claim 10, characterized by the addition of a locking member carried by the coupling arrangement for locking the said adjacent worm thereto.

l2. In a Stoker structure tube means, a pair of aligned fuel feeding Worms therein, the pitch and 5 tinuous spiral channel.

HURSHEL H.F1TCH. 

